US3550442A - Method and apparatus for measuring uniformity of tires - Google Patents

Method and apparatus for measuring uniformity of tires Download PDF

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US3550442A
US3550442A US757663A US3550442DA US3550442A US 3550442 A US3550442 A US 3550442A US 757663 A US757663 A US 757663A US 3550442D A US3550442D A US 3550442DA US 3550442 A US3550442 A US 3550442A
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Prior art keywords
tire
circuit
signal
radial runout
output
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Clide I Carr
Harry Friedmann
Haig D Tarpinian
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Uniroyal Goodrich Tire Co
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Uniroyal Inc
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Assigned to UNIROYAL GOODRICH TIRE COMPANY THE, A NY. GENERAL PARTNERSHIP reassignment UNIROYAL GOODRICH TIRE COMPANY THE, A NY. GENERAL PARTNERSHIP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: UNIROYAL TIRE COMPANY, INC., A CORP OF NJ.
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Assigned to FIRST NATIONAL BANK OF CHICAGO, THE reassignment FIRST NATIONAL BANK OF CHICAGO, THE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: UNIROYAL GOODRICH TIRE COMPANY, THE
Assigned to UGTC, INC., 600 SOUTH MAIN STREET, AKRON, OH 44397-0001, A DE CORP. reassignment UGTC, INC., 600 SOUTH MAIN STREET, AKRON, OH 44397-0001, A DE CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: UNIROYAL GOODRICH TIRE COMPANY, THE
Assigned to UNIROYAL GOODRICH TIRE COMPANY, THE reassignment UNIROYAL GOODRICH TIRE COMPANY, THE CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE ON 11/01/1990 Assignors: UGTC, INC.
Assigned to MICHELIN FINANCE (PAYS-BAS) reassignment MICHELIN FINANCE (PAYS-BAS) SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FIRST NATIONAL BANK OF CHICAGO, THE
Assigned to UNIROYAL GOODRICH TIRE COMPANY, THE reassignment UNIROYAL GOODRICH TIRE COMPANY, THE PARTIAL RELEASE Assignors: MICHELIN FINANCE (PAYS-BAS) B.V.
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/0601—Vulcanising tyres; Vulcanising presses for tyres
    • B29D30/0633—After-treatment specially adapted for vulcanising tyres
    • B29D30/0643—Cooling during post cure inflation; Post cure inflators used therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/28—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring contours or curvatures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/28—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring contours or curvatures
    • G01B7/282—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring contours or curvatures for measuring roundness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M17/00—Testing of vehicles
    • G01M17/007—Wheeled or endless-tracked vehicles
    • G01M17/02—Tyres
    • G01M17/022—Tyres the tyre co-operating with rotatable rolls
    • G01M17/024—Tyres the tyre co-operating with rotatable rolls combined with tyre surface correcting or marking means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/0601—Vulcanising tyres; Vulcanising presses for tyres
    • B29D30/0633—After-treatment specially adapted for vulcanising tyres
    • B29D2030/0634—Measuring, calculating, correcting tyre uniformity, e.g. correcting RFV
    • B29D2030/0635—Measuring and calculating tyre uniformity, e.g. using mathematical methods
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Definitions

  • the periodic signal is electronically analyzed with an analog oscillator circuit to obtain the maximum value of its first harmonic component and to determine and mark the location of this maximum value on the tire itself.
  • Associated circuitry and apparatus is disclosed.
  • the invention relates to a method and apparatus for obtaining tire uniformity measurements. More specifically, the invention relates to a method and apparatus for measuring the radial runout of a tire and to apparatus for determining the magnitude of the first harmonic como ponent of such radial runout and for determining the location on the tire of the maximum value of the first harmonic component.
  • radial runout refers to the variation in the radius of the tire as measured when it is inflated but not under load.
  • the tire may be placed on a wheel and axle assembly and slowly rotated. As the tire rotates, its tread surface contacts an indicating mechanism, such as a dial indicator or a dislpacement transducer, to thereby provide an indication of the radial runout of the tire. It has been the practice in the tire industry to make such radial runout measurements along and at or near the circumferential centerline of the tread surface of the tire. While this method of measuring tire uniformity has the advantages of being simple, fast and inexpensive, it has the very great disadvantage of not providing an adequate indication of tire performance and ride characteristics.
  • Apparatus used in making this measurement includes a wheel and axle assembly on which the tire to be evaluated is mounted and also a test-wheel which is in contact with the tire.
  • the tire is forceably held against the test-wheel, the applied force thereby providing a predetermined load on the tire, and when the test-wheel is rotated, the tire rotates with it.
  • the variation in the radial force on the axle on which the tire is mounted is measured. This radial force variation repeats itself with each revolution of the tire.
  • Such a mathematical function may be expressed as a Fourier series, the terms of which may be combined by means of trigonometric identities to form the expression where the frequency w:21r/ 1-, 7' being the period; where 6, and 6,, are phase angles of the respective terms of the infinite series; where C is a constant; where C is the amplitude of the first harmonic component of the periodic function F(t); and where C represents the amplitude of higher order harmonics. It has now been found by automotive and tire engineers that the value C of the first harmonic component of radial force variation is an important factor to be considered in the evaluation of tire uniformity with respect to the performance and ride characteristics of the tire.
  • the method and apparatus of the present invention overcomes many disadvantages of the past utilized radial runout and radial force variation. methods of measuring tire uniformity, and at the same time, combines their advantages to provide a rapid, adequate, accurate, and relatively inexpensive method for measuring uniformity of tires as related to their performance and ride characteristics.
  • apparatus for electrically averaging the radial runout on the outer tread portions or rows of a tire and to thereby obtain a periodic average radial runout electrical signal which is, for one period only, fed into an analog oscillator the output of which is proportional to the maximum value of the first harmonic component thereof.
  • circuit means are provided for detecting the point on the tire at which such maximum value of the first harmonic occurs.
  • FIG. 1 is a front elevational view of a simplified machine which illustrates the method constituting one aspect of the invention
  • FIG. 2 is an end elevational view of the machine of FIG. 1;
  • FIG. 3 is a sectional view taken along line III-III in FIG. 2, and illustrates measurement-sensing means which may be utilized to measure radial runout on the outer tread portions or rows;
  • FIG. 4 is a top view of the measurement-sensing means of FIG. 3;
  • FIG. 5 is a schematic diagram of a control circuit which may be used in conjunction with the simplified machine of FIGS. 1 and 2;
  • FIG. 6 contains various waveforms which illustrate the correlation between radial force variation measurements and measurements obtained by averaging continuously the radial runout on tread outer portions or rows;
  • FIG. 7 is a block diagram of the computation circuits which are within the confines of the invention.
  • FIG. 8 illustrates waveforms that occur at various points in the computation circuits, the waveforms being designated by Roman numerals which also appear at the appropriate points in the block diagram of FIG. 7;
  • FIGS. 9 through 19 provide detailed schematic circuit information as to those items shown in block diagram form in FIG. 7, and are as follows:
  • FIG. 9 -averaging circuit and filters
  • FIG. 10 DC suppression and gating circuit
  • FIG. 11 analog oscillator circuit
  • FIG. 13 first harmonic maximum values location detector and relay circuit
  • FIG. 14 -peak-to-peak detector circuit
  • FIG. 15 timing-pulse shaper
  • FIG. 17 outputs of sequence-controller-circuit elements with respect to timing pulses
  • FIG. 18 square-wave calibrator circuit
  • FIG. l9logic-monitor light circuit
  • a frame 1 has mounted thereon bearings 2 and 3 journalling axle 4 for rotational movement.
  • Drive means 5 are provided for slowly rotating axle 4, and wheel 6 affixed thereto, at a constant angular velocity, or speed.
  • the tire T to be measured for uniformity is mounted on wheel 6.
  • Measurement-sensing means 7a and 7b are provided for continuously contacting the outer tread portions or rows of the tire T.
  • FIGS. 3 and 4 are enlarged views of the measurement sensing means, and reference is now made thereto.
  • a cylinder 8 is provided having end blocks 9 and 10 which, in turn, are secured to base plate 11.
  • the end blocks 9 and 10 have bushings 12 and 13, respectively, mounted therein and through which shaft 14 passes enabling it to move axially with respect to cylinder 8.
  • a stop 15 is attached to shaft 14 by means of roll pin 16 and is adapted to limit the axial movement of shaft 14.
  • tie member 17 which has a slot in it through which rod 18 passes, the latter serving to prevent rotational movement of shaft 14.
  • Tie member 17 also translates the axial movement of shaft 14 to the movable element 19 of displacement transducer 20 (FIG. 2) which, preferably, is a linear motion potentiometer.
  • a clevis 21 which has a small roller 22 rotatably mounted between its forked parts.
  • measurement-sensing means 7a and 7b are mounted on base plate 11 and that base plate 11 is attached to slide plate 23 which is adapted to slide in guide means provided in bracket 24 mounted on frame 1. Movement of slide plate 23, and, therefore, of measurement-sensing means 7a and 7b, toward and away from tire T is accomplished with air cylinder 25.
  • Pushbutton PB2 also energizes time delay relay TDR which, in turn, locks itself in and energizes motor starter M1 which causes tire T to rotate. After a predetermined delay, during which the angular velocity of tire T becomes constant, timed contact TDR closes causing control relay CR2 to be energized and locked in by its normally-open contact.
  • the normallyclosed CR2 contact opens and provides a signal to the computation circuits (described below) to initiate processing of the signals obtained from the linear potentiometers 20 shown in FIG. 2.
  • timing pulses for the computation circuits are provided for each of rotation of the tire; preferably, these pulses are obtained from a magnetic pick-up (FIG. 7) which produces a pulse when either of two ferrous protrusions 180 apart on the axle moves in proximity to the magnetic pick-up.
  • a cam-driven limit switch could be utilized in lieu of the magnetic pick-up.
  • One of the functions of the computation circuits is to determine the location on the tire of the maximum value of the first harmonic component of average radial runout.
  • the computation circuit causes normally-open relay contact RC2 (FIG. 5) to close, thereby, energizing tiremarker solenoid TM (FIG. 5 and FIG. 2) which places a mark on the tire tread surface.
  • the computation circuit also causes normally-closed relay contact RC1 to open; this de-energizes time delay relay TDR, solenoid SV-2, and motor starter M1, and causes the tire T to stop its rotation and further causes the measurement-sensing means 7a and 7b to move away from the tire.
  • Pushbutton PBS is then depressed to reset the control and computation circuits for the next tire uniformity measurement.
  • tire T deflates and may then be removed from wheel 6.
  • rollers 22 of the respective measurement-sensing means 711 and 7b are in contact with the outer tread portions or rows of tire T.
  • the force of gravity may be sufficient to gently urge roller 22 against the tread surface; however, it may be necessary to provide means, such as spring force, for urging the measurement sensing means against the tread surface, as would be the case where the tire to be measured is mounted horizontally rather than vertically as shown.
  • This average radial runout signal is peri odic, with a period equal to the time for one revolution of tire T, because the variations in tire radius are repeated with each revolution of the tire.
  • FIG. 6 contains four waveforms, labeled A, B, C and D, which were obtained as a result of radial runout and radial force variation measurements made on a bias-ply, passenger-car tire.
  • Waveform A shows one complete period of radial runout of the outer tread row on one side of the tire only;
  • waveform B shows a complete period of radial runout of the tread row on the opposite side of the tire;
  • waveform C shows a complete period of average radial runout of the tire, the average being taken by continuously adding together, as the tire rotates, the radial runout measurements of both outer tread rows and then dividing the sum by two.
  • waveforms A and B are added together point by point and the sums averaged, then waveform C will be obtained.
  • Waveform D shows the tires radial force variation, measured in pounds of force. Comparison of waveform C (shown double size), the average radial runout, with waveform D establishes the similarity between the two measurements. Furthermore, it may be seen from the scales at the sides of the waveforms that one-thousandth of an inch of average radial runout is approximately equivalent to one pound of radial force variation. This high degree of correlation between average radial runout and radial force variation, which includes correlation of the maximum values and phase angles of the first harmonic components thereof, has been found to exist in a large quantity of tires examined for uniformity.
  • the computation circuits described below provide the necessary information concerning the first harmonic component of average radial runout. It must be mentioned here that the computation circuits, if desired, may also be used to determine the first harmonic component of a radial force variation signal.
  • FIG. 7 is a block diagram of the computation circuits and includes blocks designating the inputs to these circuits and the outputs therefrom.
  • the Roman numerals which appear in the block diagram correspond to the waveforms so numbered in FIG. 8.
  • the signals from the linear motion potentiometers 20 are continuously combined and averaged by the averaging circuit to obtain a periodic average radial runout signal which includes a DC component (waveform I).
  • the DC component which results from the DC voltage applied across the linear motion potentiometers, is then removed by a DC suppression circuit.
  • This average radial runout signal is then amplified and, at the command of the sequence controller, gated for one period as shown by waveform II. The amplitude of this waveform is measured with the peak-to-peak 6 detector and its output (waveform VI) is indicated on the RUNOUT PP METER.
  • the gated average radial runout signal is also fed into the analog oscillator.
  • the response of the analog oscillator to the gated input signal is transient during the sample period, but at the start of the read-out period it becomes a steadystate sine wave and continues as such thereafter as shown by waveform III.
  • the amplitude of this sine wave is proportional to the maximum value of the first harmonic component of average radial runout and is measured by the harmonic amplitude detector.
  • the output of the harmonic amplitude detector may be fed into a rejection level comparator which cornpares the harmonic amplitude with a predetermined reference value; if the harmonic amplitude exceeds such predetermined value, the comparator may be used to indicate this fact, such as by means of turning on a rejection light, and also to operate automatic means, such as a gate in a conveyor system, for rejection of the tire measured for uniformity and found by the comparator to be unacceptable.
  • the sine wave output of the analog oscillator is also fed into the harmonic maximum-value location detector.
  • This detector is of the negative-going, zero-crossing type, i.e., it detects the point, as shown by waveform V, at which the sine wave output of the analog oscillator crosses zero and then becomes negative. This point corresponds, in time, to the occurrence of the maximum value of the first harmonic component of average radial runout, and the tire marker is energized at the instant this point is reached.
  • the sequence controller governs the specific times during which the above described operations take place.
  • the entire sequence of operation of the computation circuits takes place within three tire revolutions. This time is divided by the sequence controller into three consecutive periods; the waiting period lasting for at least one-half revolution, the sample period lasting for one complete revolution, and the read-out period also lasting for one revolution.
  • Waveform IX is produced by the sequence controller during the sample period and is fed to the DC suppression and gating circuit; a suitable logic monitor light may be used to indicate the occurrence of this period.
  • Waveform X is produced by the sequence controller during the read-out period and controls operation of the harmonic amplitude detector; a suitable logic monitor light may also be used to indicate the occurrence of this period.
  • the sequence controller also produces a square wave, waveform XI, which drives the calibrator, and a print command signal, waveform XII, which may be used to energize an optional digital voltmeter-printer system.
  • FIG. 9 The details of the summing circuit and filters are shown in FIG. 9.
  • linear motion potentiometers 20 are shown in schematic form.
  • a DC voltage is applied across the potentiometers, and the voltages E and E from the respective arms thereof, these voltages being the radial runout signals from the respective outer tread portions of the tire being measured for uniformity, are applied across equal-valued resistors 31, 32, 33 and 34.
  • the output E is the average radial runout signal, including a DC component, and is equal to the sum of voltages E and E divided by two.
  • Capacitors 35 and 36 are included in the circuit for the purpose of removing possible 60-cycle .pick-u p.
  • the average radial runout signal E becomes the input to the DC-suppression and gating circuit shown in FIG. 10.
  • the DC-suppression and gating circuit removes the DC component of signal E amplifies the remaining signal, and gates it for one period. Although the DC component of signal E does not contain any harmonics, its removal is necessary because, otherwise, it would, upon amplification, cause the analog oscillator to saturate.
  • amplifier A3 is wired as an inverting, difference amplifier; its output E may be expressed as follows:
  • the output voltage E of the DC suppression and gating circuit is fed to the analog oscillator circuit which is illustrated in FIG. 11.
  • the analog oscillator circuit is the electronic analog of an undamped oscillator that obeys the equation 52( x( where F(t) is a forcing function, or input signal to the electronic analog, and is a function of time;
  • forcing function F(t) is periodic and bounded, as is a radial force variation or average radial runout signal, then, as was previously stated, it may be described by the Fourier series expression It may be shown mathematically that if such a forcing function is applied to the oscillator for one period only, such period being equal to 21r/w, then the response (t) of the oscillator to this forcing function F(t) will be sin (amt-B 8 the first harmonic component C cos (wa l-6 of F(t) is at its maximum value.
  • the analog oscillator circuit described above and hereinafter has a natural frequency in corresponding to the first harmonic frequency of the periodic and bounded forcing function F(t), this nevertheless does not limit the oscillators usefulness to measurement of the first harmonic component of such periodic and bounded forcing function F(t). Rather, if it is desired to measure the amplitude and phase angle of a predetermined higher order harmonic component of forcing function F(t), then the natural frequency of the analog oscillator circuit may be adjusted, with circuit means hereinafter described, to correspond to the frequency of such predetermined higher order harmonic.
  • the oscillator would then be the electronic analog of the equation where n designates the number of the predetermined higher order harmonic component being measured and Where to would then be the fundamental frequency of the periodic and bounded forcing function F(t). If forcing function F(t) were to be gated to the analog oscillator, for a single period only, as its input signal, then the analog oscillator response (t) would be As was earlier mentioned, the analog oscillator circuit is the electronic analog of Equation 2. When the gated average radial runout signal E is applied to this circuit, this signal corresponds to the forcing function F(t) and the analog oscillator output signal E is a sine wave the amplitude of which is proportional to the maximum value of the first harmonic component of the gated average radial runout signal B In FIG.
  • operational amplifier A4 is wired as a summing amplifier. Its output E is where R and R are resistances, E is the input signal, and E is a feedback signal from the output of amplifier A6. Operational amplifier A5 is used as an integrator. Its output E is proportional to the integral of its input E, that is,
  • Equation 6 is the value of resistor R
  • C is the value of capacitor C.
  • Operational amplifier A6 is also an integrator. Its output is where R and C are resistance and capacitance values, respectively, associated with amplifier A6 and are of the same value as those indicated by Equation 6.
  • Equation 9 becomes where Ilg is the second time derivative of E
  • Equation 5 is the value of E from Equation 5 into Equation 10
  • Equation 11 may be seen to be the electronic analog of Equation 2 wherein E corresponds to E corresponds to F(l),
  • the circuit elements enclosed by broken lines are the parts of a double-pole photocell-lamp combination.
  • the resistive elements 41 and 42 have a resistance, when they are not being exposed to light, of about 1000 megaohms, which does not affect the function of the integrators.
  • transistor Q1 is rendered conductive by the reset signal (waveform VII of FIG. 8) then lamp L is lighted and this causes the resistance of elements 41 and 42 to decrease to about only 500 ohms; this low resistance value permits capacitors C to discharge and, thereby, restores the integrating circuits of the analog oscillator to a quiescent state.
  • the oscillator is automatically reset at the completion of each tire uniformity test and made ready for a subsequent test.
  • the output signal E; from the analog oscillator circuit is fed into the harmonic amplitude detector circuit shown in FIG. 12.
  • diode D2 when transistor Q2 is rendered non-conductive by the signal from the sequence controller, diode D2 is reverse-biased since the saturation level of amplifier A6 precludes signal E, from exceeding the positive DC voltage applied to diode D2 through resistor 43.
  • diode D1 permits capacitor 44 to be charged to the maximum value of E but blocks discharge of capacitor 44 when E, begins to decrease in voltage level.
  • the voltage across capacitor 44 is the input to operational amplifier A7, which is a unity gain amplifier having a high input impedance that prevents appreciable leakage of charge from capacitor 44; the output of amplifier A7 would be the maximum value of signal E were it not for the fact that the voltage across capacitor 44 differs by a small amount from E due to the knee characteristic of diode D1. To compensate for this, a small voltage is added to the output of amplifier A7 through resistor 47 associated with operational amplifier A8 to which the signal from amplifier A7 is fed. The output E of amplifier A8 represents the corrected maximum value of the first harmonic. Signal E is designated as waveform IV in FIG. 8.
  • Transistor Q3 is used to hold the harmonic amplitude meter AM at zero until the beginning of the readout period at which time both it and transistor Q2 are rendered nonconductive. Upon completion of the read-out period, transistors Q2 and Q3 become conductive once again.
  • diode D2 forms a discharge path for capacitor 44.
  • the harmonic amplitude detector circuit is automatically reset for the next harmonic amplitude measurement.
  • the rejection level comparator circuit and the relay associated therewith are also shown in FIG. 12.
  • the operational amplifier A9 is wired as a voltage comparator in that it compares signal E which represents the harmonic maximum value, with a preset voltage, which is obtained from potentiometer 46 and which corresponds to the desired rejection level. If signal E exceeds the preset rejection level, the output of amplifier A9 renders transistor Q4 conductive. This, in turn, places transistor Q5 in the conductive state and energizes a relay having a contact RC3 which may be used to operate an indicating light and/or to operate automatic means, such as a gate in a conveyor system, for rejection of the tire measured for uniformity and found by the comparator to be unacceptable because its first harmonic component exceeded the preset rejection level. Diode D3, which is connected across the relay coil, is used to provide a discharge path for any energy which may remain in the coil after transistor Q5 becomes nonconductive.
  • the circuit which appears in FIG. 13 is the first harmonic maximum value location detector and relay circuit.
  • the input to operational amplifier A10 is signal E; from the analog oscillator circuit, signal E being a sine wave proportional in amplitude to the maximum value of the first harmonic component of the analog oscillator input signal, but 1r/2 radians out of phase with it. It is this phase difference which causes the time at which E, crosses zero in a negative-going direction to coincide with the maximum value of the first harmonic component.
  • transistor Q8 When transistor Q8 is in its conductive state, transistor Q6 cannot be rendered conductive by the positive pulses from capacitor 51, and the sequence controller holds transistor Q8 in such conductive state except during the read-out period.
  • the circuit for the peak-to-peak detector is shown in FIG. 14. This circuit is designed to measure the peak-topeak value of the average radial runout or, as the case may be, radial force variation signal being fed into the analog oscillator circuit.
  • the input to the peak-to-peak detector is signal E This signal is applied to two essentially separate peak detectors, one for detecting the maximum value and the other for detecting the minimum value. These peak detectors functions in a manner similar to that of the previously described harmonic amplitude detector.
  • transistor Q9 When transistor Q9 is in a non-conductive state, its collector is at a positive DC voltage which is in excess of the saturation level of amplifier A3 (FIG.
  • a conductive state in transistor Q9 initiated by a signal from the sequence controller, causes transistors Q10, Q11 and Q12, to conduct, thereby, shunting off the outputs of amplifiers A11 and A12 and permitting capacitors 52 and 53 to discharge through diodes D7 and D8 which are then biased to ground through transistors Q9 and Q10, respectively. This resets the peak-to-peak detector circuit for the next measurement.
  • the timing-pulse shaper circuit is illustrated.
  • the timing pulses for the sequence controller are preferably derived from magnetic pick-up means which produces a pulse for every 180 of rotation of the tire being measured for uniformity. Such pulses do not, however, have a sufficiently rapid fall time to trigger the controller circuit which requires that the fall time be less than 100 nanoseconds.
  • the pulses E from the magnetic pick-up are fed into high-gain amplifier A13.
  • amplifier A13 In order to prevent amplifier A13 from responding to possible noise signals, it is supplied with a reference voltage input E obtained from potentiometer 55; this reference voltage sets the trigger level of amplifier A13.
  • the sequence-controller circuit appears in FIG. 16. This circuit controls the sequence of events which occur in the various computation and output circuits. Preferably, the entire sequence-controller circuit is constructed with integrated circuit components.
  • J K1, J K2, and JK3 are integrated J-K type circuit flip-flop components
  • N1 through N7 are integrated circuit NOR- gate components.
  • the upper case letters A through K, which appear at output locations of the various integrated circuit components, designate the respective outputs of these components and correspond to the letters which appear at the right-hand side of the waveforms shown in FIG. 17.
  • the designations for the components which have the outputs indicated are placed at the lefthand sides of the waveforms.
  • the timing pulses and reset signal waveform are also shown in FIG. 17 to indicate the time relationships of the various waveforms to one another. Waveforms VII through XII of FIG. 8 correspond to waveforms labeled reset signal, timing pulses, G, H, B and K, respectively, in FIG. 17.
  • sequence controller circuit There are two inputs to the sequence controller circuit: the reset signal obtained from normally-closed contact CR2 in the previously described machine control circuit, and periodic pulses E obtained from the timingpulse shaper circuit (FIG.
  • the sequence controller provides output B which drives the calibrator, output G which operates the DC suppression and gate circuit, output F which controls the operation of the harmonic amplitude detector, output I which enables the harmonic maximum-value detector to operate, output I which controls the waveform peak-to-peak detector, and output K which may be used to actuate a digital voltmeter-printer system upon termination of: each tire uniformity measurement.
  • output B from the sequence controller drives the calibrator, the circuit diagram for which appears in FIG. 18.
  • Output B is a square wave generated as a result of the timing pulses which occur with each of tire rotation.
  • the calibrator circuit is simply a transistor switch circuit the output E of which is also a square wave having a DC component.
  • Square wave B is used to calibrate the overall gain of the DC suppression and gating, the analog oscillator, and the harmonic-amplitudemeter circuits.
  • the square-wave calibration signal is applied to the input of the DC suppression and gating circuit, which removes its DC component leaving only the square wave portion.
  • the square wave calibration signal may be made the input to the analog oscillator and the gain of the harmonic amplitude meter may then be adjusted so that a chosen meter scale reading corresponds to the amplitude of the first harmonic component thereof.
  • the square-wave amplitude is initially tailored, by proper choice of resistance values in the calibrator circuit, to correspond to a certain number of inches of average radial runout or pounds of radial force variation, then the harmonic amplitude meter will be capable of being read directly in such units.
  • the square-wave calibration described above is dependent upon the presupposes correct frequency calibration of the analog oscillator circuit.
  • the natural frequency w of the analog oscillator must correspond to the angular frequency of the rotating tire. Such frequency correspondence is achieved through use of the fact that the out put of the analog oscillator will theoretically be zero if a DC-voltage input is gated to it for a time equal to one period at the natural frequency w of the oscillator.
  • a regulated DC voltage is gated to the analog oscillator circuit for one period at the rotational frequency of the tire. If the output of the analog oscillator, which may be measured with harmonic amplitude meter AM, is then not equal to zero, adjustment of variable resistance R (FIG. 11) is made until the output is as nearly equal to zero as possible.
  • the natural frequency w of the analog oscillator corresponds to the angular frequency of the rotating tire.
  • FIG. 19 therein illustrated is a circuit which may be used to provide a visual indication of the occurrence in the computation circuits of either the sample or read-out periods. If the sample period is being monitored, then waveform G (FIG. 17) from the sequence controller is the input; if the read-out period were being monitored, then waveform H would be the input. If it is assumed that the sample period is being monitored, then, during this period, transistors Q14 and Q15 are rendered conductive. This causes lamp L1 to light and to remain in that condition until the end of the sample period.
  • a method for measuring the uniformity of-a tire which comprises:
  • the method of claim 8 including the additional step of electronically measuring the amplitude and phase angle of the first harmonic component of said periodic and bounded average radial runout electrical signal.
  • Apparatus for obtaining a periodic and bounded electrical signal representative of the average radial runout of a tire which comprises:
  • circuit means for continuously averaging, as the tire rotates, the two outer tread portion radial runout measurements
  • circuit means for continuously averaging, as the tire rotates, the two outer tread portion radial runout measurements comprises:
  • linear potentiometers having movable arms responsive to the respective outer tread portion radial runout measurements, said linear potentiometers being connected in parallel and having a DC voltage applied thereto;
  • equal-valued resistance means to continuously provide an output voltage equal to the average of the voltages on the arms of said linear potentiometers.
  • Apparatus in accordance with claim 12, wherein said means for measuring the radial runout of the me on its two outer tread portions comprises:
  • a base plate positioned in spaced relation with respect to the location for the tire to be measured
  • each of said sensing means having movable elements capable of continuously contracting the tread surface of the tire to be measured as it rotates, each of said sensing means being positioned on said base plate to permit the movable elements thereof to contact one of the outer tread portions of the tread surface of the tire to be measured and to permit the movable elements to respond to the radial runout of the tire at each of the outer tread portions, the movable elements of each of said sensing means being attached to the respective arms of said linear potentiometers whereby such arms are made responsive to the respective radial runouts of the outer tread portions of the tire.
  • circuit means for continuously averaging, as the tire rotates, the two outer tread portion radial runout measurements thereby to obtain a periodic and bounded average radial runout signal of angular frequency w and having a DC component;
  • circuit means for measuring the peak-to-peak value of the periodic and bounded average radial runout signal
  • circuit means for suppling a calibration signal for calibration of the overall gain of circuit means (d), (e) and (f) of claim 14;
  • circuit means for supplying a DC voltage, gated for a single period at the angular frequency of the rotating tire, to said electronic circuit means analog to permit adjustment of its natural frequency to correspond to the angular frequency of the rotating tire.
  • phase angle circuit means for determining the phase angle of the sine wave output signal, such phase angle being 1r/2 radians out of phase with the maximum value of the first harmonic component of the average radial runout input signal and therefore indicative of its 1 phase angle;
  • (h) means for marking 011 the tire the location of the maximum value of the first harmonic component of average radial runout.
  • a first operational amplifier operative as a summing amplifier
  • a second operational amplifier operative as an integrator and having as its input the output from said first operational amplifier
  • a third operational amplifier operative as an integrator and having as its input the output from said second operational amplifier, the output from said third operational amplifier constituting a feedback input to said first operational amplifier.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Testing Of Balance (AREA)
  • Tires In General (AREA)
  • A Measuring Device Byusing Mechanical Method (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Length Measuring Devices With Unspecified Measuring Means (AREA)
US757663A 1968-09-05 1968-09-05 Method and apparatus for measuring uniformity of tires Expired - Lifetime US3550442A (en)

Applications Claiming Priority (1)

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US75766368A 1968-09-05 1968-09-05

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US (1) US3550442A (xx)
JP (1) JPS4835388B1 (xx)
BE (1) BE738364A (xx)
CA (1) CA940703A (xx)
DE (1) DE1944678A1 (xx)
FR (1) FR2017452A1 (xx)
GB (1) GB1272813A (xx)
LU (1) LU59395A1 (xx)
NL (1) NL6913469A (xx)
SE (1) SE361735B (xx)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3844048A (en) * 1969-02-27 1974-10-29 N Branham Method and apparatus for stabilizing vehicles
JPS5093165A (xx) * 1973-12-18 1975-07-25
US4018087A (en) * 1975-08-14 1977-04-19 Gebr. Hofmann Kg Method and apparatus for testing the uniformity of a rotary body
JPS56151945U (xx) * 1981-03-12 1981-11-13
US4736546A (en) * 1983-07-01 1988-04-12 Ugo John W Tire uniformity grinder and method
EP0273542A2 (en) * 1986-10-17 1988-07-06 Illinois Tool Works Inc. Apparatus and method for predicting fore/aft forces generated by tires
US5537866A (en) * 1993-11-23 1996-07-23 Continental Aktiengesellschaft Method and device for correcting imbalance of pneumatic vehicle tires by removing bead material
US5639962A (en) * 1996-03-06 1997-06-17 The Goodyear Tire & Rubber Company Enhanced tire uniformity machine data utilizing first and second derivative calculations
DE19837680C2 (de) * 1998-08-19 2001-05-17 Continental Ag Verfahren zur Verbesserung des Reifenrundlaufes sowie Vorrichtung und Trommel zur Durchführung dieses Verfahrens
US20070084541A1 (en) * 2005-10-17 2007-04-19 Toyo Tire & Rubber Co., Ltd. Method and apparatus for inspecting pneumatic tire during production
CN109396741A (zh) * 2018-12-18 2019-03-01 山东河西黄金集团有限公司 一种球磨机轴头修复方法及其量规
RU2737415C1 (ru) * 2017-03-10 2020-11-30 Просек Са Зондирование конструкции из бетона при помощи электромагнитных волн

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5410292U (xx) * 1978-04-28 1979-01-23
US4414843A (en) * 1980-09-19 1983-11-15 The Goodyear Tire & Rubber Company Tire dynamic imbalance screening system
JP2009031034A (ja) * 2007-07-25 2009-02-12 Bridgestone Corp タイヤのラジアルランナウト測定方法および装置
CN107401995B (zh) * 2017-09-07 2023-06-13 四川远星橡胶有限责任公司 用于轮胎跳动量、偏摆量的检测设备

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3844048A (en) * 1969-02-27 1974-10-29 N Branham Method and apparatus for stabilizing vehicles
JPS5093165A (xx) * 1973-12-18 1975-07-25
US4018087A (en) * 1975-08-14 1977-04-19 Gebr. Hofmann Kg Method and apparatus for testing the uniformity of a rotary body
JPS56151945U (xx) * 1981-03-12 1981-11-13
US4736546A (en) * 1983-07-01 1988-04-12 Ugo John W Tire uniformity grinder and method
EP0273542A3 (en) * 1986-10-17 1990-02-07 Eagle-Picher Industries, Inc. Apparatus and method for predicting fore/aft forces generated by tires
EP0273542A2 (en) * 1986-10-17 1988-07-06 Illinois Tool Works Inc. Apparatus and method for predicting fore/aft forces generated by tires
US5537866A (en) * 1993-11-23 1996-07-23 Continental Aktiengesellschaft Method and device for correcting imbalance of pneumatic vehicle tires by removing bead material
US5639962A (en) * 1996-03-06 1997-06-17 The Goodyear Tire & Rubber Company Enhanced tire uniformity machine data utilizing first and second derivative calculations
DE19837680C2 (de) * 1998-08-19 2001-05-17 Continental Ag Verfahren zur Verbesserung des Reifenrundlaufes sowie Vorrichtung und Trommel zur Durchführung dieses Verfahrens
US6689304B1 (en) 1998-08-19 2004-02-10 Continental Aktiengesellschaft Method and apparatus for improving concentricity in automobile tires
US20070084541A1 (en) * 2005-10-17 2007-04-19 Toyo Tire & Rubber Co., Ltd. Method and apparatus for inspecting pneumatic tire during production
RU2737415C1 (ru) * 2017-03-10 2020-11-30 Просек Са Зондирование конструкции из бетона при помощи электромагнитных волн
US11275073B2 (en) 2017-03-10 2022-03-15 Proceq Sa Probing a structure of concrete by means of electromagnetic waves
CN109396741A (zh) * 2018-12-18 2019-03-01 山东河西黄金集团有限公司 一种球磨机轴头修复方法及其量规

Also Published As

Publication number Publication date
BE738364A (xx) 1970-03-03
SE361735B (xx) 1973-11-12
LU59395A1 (xx) 1970-01-07
JPS4835388B1 (xx) 1973-10-27
CA940703A (en) 1974-01-29
NL6913469A (xx) 1970-03-09
FR2017452A1 (xx) 1970-05-22
GB1272813A (en) 1972-05-03
DE1944678A1 (de) 1970-03-12

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